RESUMO

The genus Mytilus comprises a large number of bivalve mollusk species distributed throughout the world and many of these species are considered invasive. In South America, many introductions of species of this genus have already taken place, including reports of hybridization between them. Now, the occurrence of the Mediterranean mussel Mytilus galloprovincialis is reported for the first time from the Brazilian coast. Several specimens of this mytilid were found in a shellfish growing areas in Florianópolis and Palhoça, Santa Catarina State, Brazil. Morphological analysis of the shells and molecular analysis through sequencing of the cytochrome oxidase subunit 1 (COI) confirmed the taxonomic identification. The species is known for its great invasive potential and can become a major environmental problem for seafood business and coastal communities, as it can compete and even hybridize with local species.(AU)

Assuntos

RESUMO

The genus Mytilus comprises a large number of bivalve mollusk species distributed throughout the world and many of these species are considered invasive. In South America, many introductions of species of this genus have already taken place, including reports of hybridization between them. Now, the occurrence of the Mediterranean mussel Mytilus galloprovincialis is reported for the first time from the Brazilian coast. Several specimens of this mytilid were found in a shellfish growing areas in Florianópolis and Palhoça, Santa Catarina State, Brazil. Morphological analysis of the shells and molecular analysis through sequencing of the cytochrome oxidase subunit 1 (COI) confirmed the taxonomic identification. The species is known for its great invasive potential and can become a major environmental problem for seafood business and coastal communities, as it can compete and even hybridize with local species.

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INTRODUCTION: This research aimed to identify and quantify potentially pathogenic Vibrio from different cultivations of bivalve shellfish in the State of Santa Catarina, Brazil, and water regions in the South Bay, as well as correlate the incidence of these microorganisms with the physicochemical parameters of marine waters. METHODS: Between October 2008 and March 2009, 60 oyster and seawater samples were collected from six regions of bivalve mollusk cultivation, and these samples were submitted for Vibrio counts. RESULTS: Twenty-nine (48.3%) oyster samples were revealed to be contaminated with one or more Vibrio species. The Vibrio parahaemolyticus and Vibrio vulnificus counts in the samples ranged from < 0.5 log10 Most Probable Number (MPN) g(-1) to 2.3 log10 MPN g(-1) oyster and from < 0.5 log10 MPN g(-1) to 2.1 log10 MPN g(-1) oyster, respectively. Of the 60 seawater samples analyzed, 44 (73.3%) showed signs of contamination with one or more vibrio species. The counts of V. parahaemolyticus and V. vulnificus in the samples ranged from < 0.3 log10 MPN·100mL(-1) to 1.7 log10MPN·100mL(-1) seawater and from < 0.3 log10 MPN·100mL(-1) to 2.0 log10 MPN·100mL(-1) seawater, respectively. A positive correlation between V. vulnificus counts and the seawater temperature as well as a negative correlation between the V. parahaemolyticus counts and salinity were observed. CONCLUSIONS: The results suggest the need to implement strategies to prevent vibrio diseases from being transmitted by the consumption of contaminated bivalve shellfish.

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RESUMO

Introduction This research aimed to identify and quantify potentially pathogenic Vibrio from different cultivations of bivalve shellfish in the State of Santa Catarina, Brazil, and water regions in the South Bay, as well as correlate the incidence of these microorganisms with the physicochemical parameters of marine waters. Methods Between October 2008 and March 2009, 60 oyster and seawater samples were collected from six regions of bivalve mollusk cultivation, and these samples were submitted for Vibrio counts. Results Twenty-nine (48.3%) oyster samples were revealed to be contaminated with one or more Vibrio species. The Vibrio parahaemolyticus and Vibrio vulnificus counts in the samples ranged from < 0.5 log10 Most Probable Number (MPN) g–1 to 2.3 log10 MPN g–1 oyster and from < 0.5 log10 MPN g–1 to 2.1 log10 MPN g–1 oyster, respectively. Of the 60 seawater samples analyzed, 44 (73.3%) showed signs of contamination with one or more vibrio species. The counts of V. parahaemolyticus and V. vulnificus in the samples ranged from < 0.3 log10 MPN·100mL–1 to 1.7 log10MPN·100mL–1 seawater and from < 0.3 log10 MPN·100mL–1 to 2.0 log10 MPN·100mL–1 seawater, respectively. A positive correlation between V. vulnificus counts and the seawater temperature as well as a negative correlation between the V. parahaemolyticus counts and salinity were observed. Conclusions The results suggest the need to implement strategies to prevent vibrio diseases from being transmitted by the consumption of contaminated bivalve shellfish. .

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Esta investigação teve como objetivo efetuar o monitoramento da qualidade higiênico-sanitária em ostras (Crassostrea gigas) e águas salinas de fazendas marinhas da Baía Sul da Ilha de Santa Catarina, por meio de microrganismos indicadores, durante o período de um ano. As amostras de ostras e águas salinas foram submetidas a ensaios microbiológicos para enumeração de coliformes a 35°C, coliformes a 45°C e Escherichia coli. Foram avaliados os parâmetros físico químicos de temperatura, salinidade, turbidez e pH nas águas e pH nas ostras. Foram observadas correlações positivas entre as contagens de coliformes a 35°C, coliformes a 45°C e E. coli nas amostras de águas salinas e de carne das ostras; e diferenças estatisticas significativas foram verificadas entre as contagens de coliformes a 45°C nas amostras de águas salina provenientes da região E. Os parâmetros físico-químicos apresentaram pouca ou nenhuma correlação estatística com as contagens bacteriológicas. Considerando-se a Baía Sul em toda sua extensão, observou se a influência do índice pluviométrico sobre as contagens bacteriológicas obtidas nas águas e nas ostras. As contagens de coliformes a 45°C observadas nas águas salinas estavam de acordo com os parâmetros descritos na legislação brasileira, contudo, ressalta-se a importância da implantação de saneamento básico em regiões de cultivo de moluscos bivalves, assim como o constante monitoramento bacteriológico de indicadores de qualidade nas águas e nos moluscos.

This investigation was conducted for one year in order to monitor the hygienic sanitary conditions of oysters(Crassostrea gigas) and saline waters from sea farms at the South Bay of Santa Catarina Island, by means ofmicroorganism indicators. Oysters and saline waters samples were assayed by bacteria counting techniquefor coliforms at 35°C, coliforms at 45°C and Escherichia coli. Physical and chemical parameters were assessedin water samples (pH, salinity, turbidity and temperature) and oyster samples (pH). Positive correlations oncoliform counts at 35°C and at 45°C, and E. coli were observed within saline waters and samples of oyster meat.Statistically significant differences on coliforms counting at 45ºC were observed among saline water samplescollected from the region E. Physical-chemical parameters showed somewhat no statistical correlation with microorganism counting. Nonetheless, the influence of rainfall indices in the Great Florianopolis region over the bacteriological counting in saline waters and oysters could be observed. The coliforms counting at 45°C in saline water samples complied with the parameters established by the Brazilian legislation, although the basicsanitation at bivalve shellfish growing sites and a regular bacteriological quality monitoring by using specificindicators are demanded for the culturing water and for growing oysters.

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RESUMO

This investigation was conducted for one year in order to monitor the hygienic sanitary conditions of oysters (Crassostrea gigas) and saline waters from sea farms at the South Bay of Santa Catarina Island, by means of microorganism indicators. Oysters and saline waters samples were assayed by bacteria counting technique for coliforms at 35C, coliforms at 45C and Escherichia coli. Physical and chemical parameters were assessed in water samples (pH, salinity, turbidity and temperature) and oyster samples (pH). Positive correlations on coliform counts at 35C and at 45C, and E. coli were observed within saline waters and samples of oyster meat. Statistically significant differences on coliforms counting at 45ºC were observed among saline water samples collected from the region E. Physical-chemical parameters showed somewhat no statistical correlation with microorganism counting. Nonetheless, the influence of rainfall indices in the Great Florianopolis region over the bacteriological counting in saline waters and oysters could be observed. The coliforms counting at 45C in saline water samples complied with the parameters established by the Brazilian legislation, although the basic sanitation at bivalve shellfish growing sites and a regular bacteriological quality monitoring by using specific indicators are demanded for the culturing water and for growing oysters.

Esta investigação teve como objetivo efetuar o monitoramento da qualidade higiênico-sanitária em ostras (Crassostrea gigas) e águas salinas de fazendas marinhas da Baía Sul da Ilha de Santa Catarina, por meio de microrganismos indicadores, durante o período de um ano. As amostras de ostras e águas salinas foram submetidas a ensaios microbiológicos para enumeração de coliformes a 35C, coliformes a 45C e Escherichia coli. Foram avaliados os parâmetros físico-químicos de temperatura, salinidade, turbidez e pH nas águas e pH nas ostras. Foram observadas correlações positivas entre as contagens de coliformes a 35C, coliformes a 45C e E. coli nas amostras de águas salinas e de carne das ostras; e diferenças estatísticas significativas foram verificadas entre as contagens de coliformes a 45C nas amostras de águas salina provenientes da região E. Os parâmetros físico-químicos apresentaram pouca ou nenhuma correlação estatística com as contagens bacteriológicas. Considerando-se a Baía Sul em toda sua extensão, observou-se a influência do índice pluviométrico sobre as contagens bacteriológicas obtidas nas águas e nas ostras. As contagens de coliformes a 45C observadas nas águas salinas estavam de acordo com os parâmetros descritos na legislação brasileira, contudo, ressalta-se a importância da implantação de saneamento básico em regiões de cultivo de moluscos bivalves, assim como o